Electronic interaction between d electron-poor and d electron-rich transition metal ions promoted the CO2 capture performance of calcium-based adsorbent

The investigation of intrinsic principles for the more precise design CaO adsorbent with excellent CO 2 capture performance by doping metal oxides is of great significance, but has not yet been explored. Herein, we address the critical challenge by systematical evaluation on a series of magnetic bimetallic oxides doped calcium-based adsorbents from the perspective of electronic interaction between d electron-poor and d electron-rich transition metal ions promoting the CO 2 capture performance. The Mn, Co, Mo and Ni metal ions with varied d -electron numbers are doped into calcium-based adsorbent, and the results show that the introduction of magnetic bimetallic oxides with d electron-poor and d electron-rich transition metal ions into CaO at the same time can significantly promote the stability of CO 2 capture. Taking the (Mn-Co)-codoped samples as an example, the relationship of d electron-poor and d electron-rich transition metal ions synergistic interaction and promoted CO 2 adsorption performance is elucidated. The loose flake nanostructures favor the diffusion of CO 2 inside the particles, and the uniform distribution of each component effectively ensures the double-exchange interactions. The generation of more oxygen vacancies significantly improves the CO 2 affinity for the calcium-based sample. Furthermore, the results of kinetic analysis reveal that the synergistic interaction can reduce the apparent activation energy of carbonation reaction. These insights into the systematical regulation of the double-exchange interaction are expected to provide guidance for the relatively more precise design of the calcium-based adsorbent with high performance of CO 2 adsorption.